Electric switch.



E. T LOOKARD.

ELECTRIC SWITCH.

APPLIUATION FILED AUG. 4, 19.09. 1 1,021,540, Patented Mar. 26, 1912.

3 SHEETS-SHEET 1.

COLUMEXA PWOORAPH c0.. WASHIPWTON. D; C.

E. T. LQCKARD. ELECTRIC -SWITCH.

APPLICATION FILED AUG. 4. 1909.

Patented Mar. 26, 191 2.

3 SHEETS-SHEET 2.

COLUMBIA PLANUGRAPH 60., WASHINGTON, D. c.

E. T. LOGKARD.

ELECTRIC SWITCH.

APPLICATION FILED AUG. 4, 1909.

Patented Mar. 26, 1912.

COLUMIIA PLANOOAPH CO" 'IAIHINUTON. D. C.

EARL T. LOCKARD, 0F CINCINNATI, OI-IIO.

ELECTRIC SWITCH.

Specification of Letters Patent.

Patented Mar. 26, 1912.

Application filed August 4, 1909. Serial No. 511,130.

To all whom it may concern:

Be it known that I, EARL T. LOCKARD, a citizen of the United States,residing at Cincinnati, in the county of Hamilton and State of Ohio,have invented certain new and useful Improvements in Electric Switches,of which the following is a specification.

My invention relates to electric switches and is primarily intended foruse in connection with motor-driven adding machines, but may also beemployed in other relations in which it is desired to form the electriccircuit while the operator of the machine to which the current isfurnished is in position for using the machine, the circuit beingimmediately opened upon the operator leaving his position.

One of the objects of my invention is to provide a switch of novelconstruction which the operator must maintain closed by some action onhis part so that the switch willautomatically open immediately that theoperator leaves his operating position, and thus save current and avoidthe operation of the motor or electric device at times when the same isnot performing work.

The invention will be further readily understood from the followingdescription and claim, and from the drawings, in which latter:

Figure 1 is a perspective view of my improved device showing the same inconnectioir with a motor-driven adding machine. Fig. 2 is .a sideelevation of my improved device, showing the switch open, and having theside of the casing broken away for better illustration of parts. Fig. 3is a similar view of the same showing the switch closed in full lines,and the lever in inoperative position in dotted lines. Fig. 4 is a planview of my improved device with the top of the casing broken away forbetter illustration of parts. Fig. 5 is a horizontal section on the line22 of Fig. 2, with the cover, the levers and the catch removed. Fig. 6is a front elevation of my improved device with the operating leverdepressed and the front of the casing removed. Fig. 7 is a detail on theline yy of Fig. 4 showing the mounting of the contact-bridge; and, Fig,8

- is a front elevation of my improved device with the operating leverdepressed.

1 represents the casing of my improved switch, which is preferablyportable, 2 represents an adding machine, and 3 the motor by which theadding machine is driven. The switch is electrically connected with themotor by proper conductors in a cable 4, the current being supplied fromany suitable source of electricity through electric conductors in acable 5 having at its end a suitable plug 6 fitting an incandescent lampsocket.

The casing may comprise a bottom 8 and a back 9, and a cover 10 suitablysecured to the bottom and back, and having a slot 11 in its front wall.

12 is a base of non-conducting material, suitably secured to the bottom8, upon which the operative parts of the switch are supported.

A suitable socket 15 is secured to the back 9 and receives a plug 16 towhich the conductors 17 18 of the cable 5 are attached, the conductor 17being electrically connected with the threaded part 19 while theconductor 18 is connected with the axial terminal 20 of said plug. Thesocket 15 comprises the threaded wall 21 with which the threaded part 19of the plug 16 makes electrical connection, the socket also beingprovided with an axial terminal 22 with which the axial terminal 20 ofsaid plug makes electrical contact.

26 27 represent separated terminals of the switch and are suitablysecured to the base 12. An electric conductor 28, which is preferably afuse, connects the terminal 26 with the lug 29 which has electricconnection with the threaded wall 21 of the socket.

31 32 are electric conductors in the cable at between the switch and thepoint of electric application represented by the motor 3. The conductor31 is electrically connected with the terminal 27 and the conductor 32is electrically connected with lug 33 electrically connected with theaxial terminal 22 of the socket 15.

35 is a lever pivoted at 36 to standards 37 secured to the base. Thislever is preferably of non-conducting material, for instancenon-conducting fiber. A bridge 38 is secured to the lever forelectrically spanning the gap between the terminals 26 27. This bridgepreferably comprises a curved spring-bar 39 shown bent in the form of anarc, to the respective ends of which shoes 40 41 are secured, theseshoes being arranged to respectively engage the terminals 26 27 forelectrically spanning the gap between said terminals. The bar is securedto the lever preferably by means of a U-clip 42, the

shanks of which are received loosely through apertures 43 in said bar,the bar and clip eX- tending longitudinally of the lever, by which meansI obtain a rocking motion between the shoes and insure that properelectric connect-ion be made between both shoes and their respectiveterminals. At the same time the relative movement between the bridge andlever is limited so that the shoes may not drag upon either terminal.

46 is an operating lever pivoted at 47 to standards 48 secured to thebase 12. This operating lever comprises an operating arm 49, shown as atreadle, and an arm 50 from which the lever 35 is operated, these armshaving a connecting member 51 between them. A spring 52 normally drawsthe operating lever into inoperative position. When in inoperativeposition, a spring 53 between the base and the lever 35 moves the latterlever into inoperative position for removing the contacts thereon fromthe separated terminals of the switch.

If the operator desires to operate the adding machine, he will place hisfoot on the treadle 49, thereby depressing the treadle and holding thesame depressed until he has completed his additions on the addingmachine. The treadle is shown as a thin flat bar, so that the same mayremain under the foot of the operator without inconvenience to him. Thedepression of this treadle will force the forward end of the lever 35upwardly, thereby depressing that end on which the electric contacts arelocated, placing the contacts into electric connection with theseparated terminals 26 27, a pin 54 on said latter end being receivedunder a latch 55 pivoted at 56 to a plate 57 secured to the base andurged into interfering position with the pin by a spring 58. The latchhas a receding face 59 against which the pin engages in its passageunder the latch.

61 is a rod which connects the latch with the operating lever. The rodpasses loosely through an aperture 62 in the shank of the latch and hasa head 63 which limits the movement of the rod toward the lever. The rodalso passes loosely through an aperture 64 in a lug 65 on the operatinglever, there being nuts 6667 received over the threaded end 68 of saidrod. The object of the connection between the latch and the operatinglever is to control the release of the switch for causing the same torelease with a snap movement to prevent arcing in the switch. When thetreadle is moved into depressed position the lug 65 will passlongitudinally of the rod for providing a space 69 between he willremove his foot from the operating lever, causing the same to spring upby reason of the spring 52. During the first part of its movement thelug 65 will pass through the space 69. In the meantime the inner end ofthe operating lever is moving away from the contactlever 35 which isheld in place by the latch 55. At approximately the limit of upwardmovement of the treadle, the lug 65 will have made contact with the nut66 and moved the same and the rod 61 sufficiently to trip the latch 55,causing the same to move out of range of the pin 54:, whereupon thelever 35 is released and the shoes 4:0 ll spring upwardly from theseparated terminals of the switch. The bottom and base are provided witha slot 7 0 for receiving the operating lever when depressed, the slot 70registering with the slot 11 in the front wall of the cover.

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent is:

In an electric switch of the character described, the combination of acasing provided with a bottom, normally separated electric terminalstherein, a connecting part for said terminals, an operating leverpivoted to said casing and provided with an operating treadle projectingoutside said casing, a lock for said connecting part for maintaining thesame in contact with said terminals, there being a spaced connectionbetween said lock and operating lever for permitting the first part ofthe movement of said operating lever to be idle with relation to saidlock, the said connection arranged to release said lock during thelatter part of said movement of said operating le-' ver, and means formaintaining said operating treadle in normally elevated position, andsaid operating treadle arranged to be depressed by the foot of theoperator into substantial line with said bottom, said op erating treadlewhen so depressed being located below the horizontal plane of saidterminals, substantially as described.

In testimony whereof, I'have signed my name hereto in the presence oftwo subscribing witnesses.

EAR-L T. LOCKARD. Witnesses:

LILLIAN BURNETT. CARL LEI-IMANN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

